JoeBliksem
New Member
- Joined
- Mar 3, 2022
- Messages
- 5
Hi, I've been struggling with this board for weeks and it's just not coming right.
History
Ignore the large ICs in this image, I'm using all original MOS chips
I'm pulling my hair out at this stage. Please help!
History
- I had a spare working drive that I wanted to convert to a Meanwell switching PSU because the drive is 110v and I live in a 240v country.
- The conversion worked and I was able to read and format upon my first tests.
Ignore the large ICs in this image, I'm using all original MOS chips
- I was a bit careless, trying to repair multiple drives, both Alps and Newtronics, and I suspect, at some point, I plugged in P8 wrong way around during subsequent testing. Either way, L8 went up in smoke.
- I swapped L8 and C15 with good parts, the drive started up and initialised normally but it would no longer read or format (File not found)
- I then swapped out all of the IC's related to FILE NOT FOUND as recommended by Ray Carlsen's guide.
- After replacing UA1 and adding a socket, the drive no longer initializes normally and just spins continuously with the red LED on.
- Even after returning the original UA1 it is still doing this. The original UA1 IC works in other drives.
- I thought perhaps it's the socket, so I removed the socket and replaced it with a new one.
- I can't see any damage or corrosion on the board.
- I have since swapped out almost every IC on the board (except RAM and Motor Controller) and the problem persists.
- I don't have an oscilliscope but I am getting odd multimeter readings e.g. the 6502 pin 40 goes to 3.8v instead of the expected 5v.
- Reading 1.9v across C15 but getting 11.9v at C21
I'm pulling my hair out at this stage. Please help!
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